SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '75fb60620a16fe31204a86e1a7475a1d330a82f7cc9e1c5fe48ade90721ba7c2' 
  AND token = 'OB5bucahlpRt0vWMLVrdA2wGH7CRBngH5t6/xYphyFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}